Hot top stripper



April 13, 1948. w. w. URMETZ HOT TOP STRIPPER Filed Aug. 24, 1944 2Sheets-Sheet 1 14 7- TOR Y5 April 13, 1948. w. w. URMETZ HOT TOP sTRIrEnFiled Aug, 24, 1944 ZSheets-Sheet 2 INVENTQ BY [Mars/e WZ/EMETZ PatentedApr. 13 1948 T HOT TOP STRIPPER Walter W. Urmetz, Parma, Ohio, assignorto The Ferro Engineering Company, Cleveland, Ohio, a corporation of OhioApplication August 24, 1944, Serial No. 551,008

3 Claims. 1

This invention relates to improvements in hot top strippers, that is tosay, mechanism operated by a crane for breaking a hot top loose from thesinkhead portion of an ingot or from the ingot mold, and transporting itto a servicing bench or other desired location. Mechanism of thischaracter must be rugged and certain in its operation, and should beadapted for use in connection with more than one size or style of hottop in order to be of the greatest usefulness in the average steel mill.

One of the objects of the present invention therefore is the provisionof a simple and rugged hot top stripper which shall be capable of easyand certain operation undervarying conditions.

Another object is the provision of a stripper mechanism which may behandled entirely by the crane operator, that is, without a helperiforadjusting the hooks, etc. i

,Another object is the provision of a stripper having readilyinterchangeable hook assemblies for ,use upon hot tops of diflerentsizes.

Other objects and features of novelty will appear as I proceed with thedescription of that embodiment of the invention which, for the purposesof the present application, I have illustrated in the accompanyingdrawings, in which Fig. 1 is an elevational view, partly broken away andpartly in section, of a hot top stripper embodying the invention. i

Fig. 2 is an elevational view of the same taken at right angles to Fig.l. i

Fig. 3 is a horizontal sectional view taken substantially along the line3-3 of Fig. 1, and Fig. 4 is a vertical sectional view takensubstantially along the line 4-4 of Fig. 1.

When in use with a crane the device of this invention is intended toexert a lifting effort upon the trunnions H at the same time that itpushes downwardly upon the sinkhead Ill within the hot top, therebybreaking the hot top loose from the ingot or mold. Thereafter continuedlifting effort applied to the trunnions ll raises the hot topsufiiciently to clear the ingot, after which it may be transported bythe crane to any desired location.

The stripper comprises a housing I 2 which may be constructed of twoheavy steel plates 13 disposed parallel to each other and preferablyrather close together. These plates may be interconnected by suitablefastenings and spacers, as for example by pins or bolts l4 and I5 andspacing elements l6 and I1. The spacers I! have downwardly directedportions l8 which form guides for a plunger I9 that slides between theslide plates 13 of the housing and is provided on op posite sides withracks 20. Across the upper end of this plunger there is a plate 9 havingprojecting portions adapted to engage the top of the housing and tothereby limit the downward movement of the plunger.

Two gears 2| meshing with the racks are rotatably mounted upon shafts22, the ends of which are mounted in the housing plates l3. These gearsaremaintained in mesh with the racks 20 at all times except when theplunger is down as far as it will go, when the gears are cleared byrecesses 23 in the racks and are then free to turn independently of theracks. At all times, however, the gears are maintained in correctrelation to eachother by spring fingers 24 which yield readily butpresent sufficient frictional resistance to prevent spinningoraccidental move-' ment of the gears. 1

20 As shown in the drawings the racks 2B terminate a-bovethe bottom ofthe plunger [9, and their lower ends may be engaged by latches 25 biasedtoward the latching position illustrated in Fig. 1.

These latches are pivoted at 26, and have bifurcated upper arms21 whichstraddle the gears 2! and bring the centers of gravity of the latchessufliciently to one side of the pivots 26 to cause the latches to swinginto latching position when they are otherwise free to do so. When thelatches are withdrawn and the plunger is free to descend below theposition illustrated in Fig. the lower ends of the latches ride freelyover the rack teeth.

Each ofthe gears 2| is straddled by the inner bifurcated end of a-leverarm 3!! which turns freely on the shaft 22. Connecting the bifurcationsthere is a pin 3! upon which is oscillatably mounted a pawl 32 havingtwo lobes 33 and 34. A coil spring 35 mounted on a telescoping pinbetween center 35' on the lever arm and center 35" on the pawl yieldablyholds either of the lobes 33 and 34 in engagement with the teeth of thegear. Shifting of the pawl from one operative position to the other maybe done manually through the open end of the housing. When the lobe 33is in operative position, as illustrated in Fig. 1, the lever arm 30 mayswing downwardly. the lobe 33 of the pawl riding over the teeth of thegear with out imparting any motion to the latter. When, however, thelever arm 30 is swung upwardly, the pawl functions to lock the lever armto the gear and rotates the latter, which communicates downward pressureto the corresponding rack 20 and thus to the plunger l9. l

plished by providing on each side of the device a knockout 138, whichmay be conveniently formed on the spacer block II, this knockout beingso formed and positioned that when the leverar m is swung upwardly to apredetermined extent, the knockout will engage the pawl 32 and swing itagainst the action of spring 35 into theposition shown in broken lineson the left side of Fig. 1, that is far enough to disengage lobe 33 fromthe gear teeth but not far enough to throw the pawlover'center, theknockout 38 being formed with a reverse curve 38' fitting the contour ofthe pawl to prevent such overthrow. The gears and racks are :thenreleased'and'are free tomove independently'of the lever arms 3%.

The levers 30 are bifurcated also at their outer ends where they carrypivots 40 upon which are mounted the lower-ends of a pair of rigid linksM. The upper ends of these links are pivotally mounted ate-2between-depending lips'of a plate 53 which may have a hole 44therethrough to be engaged by a crane 'hook.

The lever arms -30 are closely confined within the Walls 13 f thehousing, while the (links 1H are=closely confined-at their lower endsbetween the outer bifurcations of lever arms 33 and at their upper endsbetween the depending lips *of the plate 43. Hence, under all conditionsthe only possible movement of the lever arms and links relative to thehousing I2 in the median plane of that housing, and movement in anyother-direction given to the links 4| through the plate 43 iscommunicated i'n the same degree to the housing to produce bodilymovement thereof. This is important'during the manipulation of thedevice required for bringing it into operative relation with a hot-top.

Two pins or bolts "45 are 'removablymounted in the walls "I3 *of thehousing. These pins or bolts serve to secure to the housing a hookassembly. The different parts of this assembly are interconnected andthe assembly when mounted in the'housing is'rigid with respect thereto.The assembly comprises two rails 46, to one of which there are connectedpermanently a pair of upwardly extending ears-4l,'perforated to receivethe removable pins '\45. To the other rail 46 there are connected twolegs 48, similarly provided with holes at their upper ends to receivethe removable pins 45. At theends of this assembly there are mounted thetwo hooks 49, the latter bridging the 'spac'e'betwe'en the rails 46andsecured thereto as well asto the ears 41 and the legs 48. Inorder toassist inlocating the assembly when it is to be mountedin the housingand to brace it whenso mounted, the upper ends of the hooks 49 may beturned inwardly as shown at fiii to engage with more or less wedgingaction the inclined portions of spacer block Hi. In the usual steel millseveral of these hook assemblies so designed that the hooks aredifferently spaced, will be required in order toaccommodate hot tops ofdifferent sizes. The-legs 48 are so dimensioned that when they are.permittedto rest upon the upper surf-acacia hot top and are draggedacross it to position the hooks 49 with respect to the trunnions II, thetips 5| of the hooks will clear the trunnions, after which a liftingeffort exerted by the crane will cause the hooks to engage thetrunnions, as in Fig. 2.

Operation. Assuming that the plunger is latched in its raised position,as in full lines in Fig. 1, and that the stripper-is hanging from acrane, that is that both'sets of lever arms and links are in the upperposition indicated by broken lines at the left side of Fig. 1, at whichtime the gears are free from the lever arms 30 but are held fromrotation by their engagement with theracks 2'0, the crane operatorcauses the jcraneto' move into position above the hot top and lowersthe-stripper until the legs 48 thereof engage the upper. surface of thehot top. Next he moves the crane to drag the legs over the hot top andposition the hooks underneath the trunnions H. The housing now restsupon the hot top. Next the operator lowers away, permitting the links 4|to descend and the lever arms 30 to swing down to the limit of theirmotion in that direction, the lobes .313 of the pawls ratcheting overthe teeth of the gears. Near the bottom of the swing of the lever armsthe lugs 3 push the latch arms 21 inwardly, which brings about therelease of the racks when the plunger descends due to gravity, the gears21 turning idly; Plunger it falls until it engages the upper surfaceofithe sinkhead H) in the hot top, the rounded lower ends of thelatches'25 riding "over the teeth of the racks 2E). The operator thencauses the crane to exert an upward pull on the plate "43 .which.operates through the links toswing the lever arms 33 upwardly. The armswhen movinginthis direction are locked to the gears 2i *byt'he lobes 33Oif the pawls.

The upward movement of the lever arms first causes the gears to rideupon thenow fixed racks 20, which imparts anupward movement :to thehousing I 2, lifting the legs 48off the hot top'and causing the hooks toengage the trunnions -l I, as in Fig. 2. Further lifting effort bythecran is then divided between the downward'pressur'e on the plungerand the upward pull on the hous ing providing mechanical advantage inarati'o of the order of 1 to '3 or 4. This breaks the .hot top loosefrom the ingot or the mold, or both, as the case may be, after which thefirst. effect. is continued, that is the gears climb up the :racks 20,lifting the housing and with it 'thehotjitop. When the arms 30 reach thelimit of their upward movement relative to the housing they then exerttheir lifiting effort through thepins 22 Ian'dthe whole mechanism movesupwardly with the hot top in its grasp.-

At the upward limit of movement of the lever arms with respect to thehousing the pawlslii are disengaged. The weight of the plunger causes itto fall until stopped by the plate 9 engaging the top of the housing.Thecrane is then oper-.- ated to transport the hot top to the desiredlocation, whenitis lowered and the hooks 49 die.- connected from thetrunnions l I. Next the -stri-pper is lowered over some previouslyprepared "upwardly extending projection which is-of -a.-char.-- acter toengage only the plunger l 9. During this operation the pawls 32 are heldinoperativewbecause of their engagement with knockouts 38,-\so that thegears 2| are free to ride idlyas the housing descends relativeto theplunger. At the end of this operation the latches :25 become-eiectiveautomatically --to latch up the :plunger relativesto.

the housing, and the stripper is then ready for use upon the next hottop.

The lobes 34 on the pawls 32 do not come into use in the ordinaryoperation of the stripper. However, in the event that the device shouldbe used upon a hot top which is so firmly locked to an ingot that itcannot be pulled loose, the parts may become jammed and diillcult todislodge, in which case the operator may flip the pawls 32 over to freethe lobes 33 and cause the lobes 34 to engage the gear teeth, whereupondownward pressure on the outer ends of lever arms 30 will cause thehousing to move downwardly relative to the plunger and thereby disengagethe hooks 49 from the trunnions II, when the whole device may be liftedout of the way and extraordinary methods employed to free the hot topfrom the ingot.

In cases where the sinkhead is low in the hot top and particularly wherethe internal diameter of the hot top is small relative to thecross-sectional size of the plunger, it may be diflicult to disengagethe stripper from the hot top. In such event the difficulty may beovercome by the employment of a chain, (not shown) which may beconnected to the plate 43 through a hole 60 therein and to a hook 6| inthe top of the plunger. The plunger is necessarily heavy because a heavyforce must be exerted through it. Its mass may be greater than theeffective mass of the lever arms 30 and the links 4|, so that with thelobes 34 of the pawls in engagement with the gears,

, lowering of the plate 43 may not be effective to raise the plunger. Insuch case the plate 43 is lowered with the lobes 33 clicking on thegears, then the pawls 32 are shifted to cause the lobes 34 to engage thegears,after which the chain is connected between the plate 43 and thehook 6|. Now the crane is caused to pull upwardly on the plate 43 andhence on the plunger, causing the lower end of the plunger to clear thehot top. This of course turns the gears, but such turning motion ispermitted by the clicking of the lobes 34 without communicating anyforce to the lever arms. The length of thechain is such that, when theplate 43 is in its uppermost position and the plunger is latched up, thechain will be taut; in

other words the chain is of such length that when the plate 43 is raisedto its uppermost position relative to the housing the plunger will beraised sufliciently to permit latches 25 to become eifective forlatching up the plunger.

Having thus described my invention, I claim:

'1. In a hot top stripper, a housing, a plunger vertically slidabletherein adapted to bear at its lower end against a sinkhead, a rack onsaid plunger, a gear journaled in said housing meshing with said rack, alever arm pivotally mounted to turn about the axis of said gear, a pawlon said arm adapted to engage the teeth of said gear for operativelyconnecting the lever arm to the gear during the upward motion of thearm, while permitting the arm to move downwardly,

independently of the gear, means carried by the,

housing for engagement with the hot top to exert 6 a lifting forcethereupon in opposition to the said plunger depressing force, and aknockout for said pawl at the upper limit of motion of saidlever arm,leaving said gear free to turn in response to movement of said plunger.

2. In a hot top stripper, a housing, a plunger vertically slidabletherein adapted to bear at its lower. end against a sinkhead, a rack onsaid,

plunger, a gear journaled in said housing meshing with said rack, alever arm pivotally mounted to turn about the axis of said gear, a pawlon said arm adapted to engage the teeth of said gear for operativelyconnecting the lever arm to the gear during the upward motion of thearm, while permitting the arm to move downwardly independently of thegear, means carried by the housing for engagement with the hot top toexert a lifting force thereupon in opposition to the said plungerdepressing force, latching means for holding said plunger in a raisedposition, said latching means being biased toward latching position, andmeans on said arm for withdrawing said latching means when said arm islowered to a predetermined extent.

3. In a hot top stripper, a housing, a plunger vertically slidabletherein adapted to bear at its lower end against a sinkhead, a rack onsaid plunger, 2. gear journaled in said housing meshing with said rack,a lever arm pivotally mounted to turn about the axis of said gear, apawl on said arm adapted to engage the teeth of said gear foroperatively connecting the lever arm to the gear during the upwardmotion of the arm, while permitting the arm to move downwardlyindependently of the gear, means carried by the housing for engagementwith the hot top to exert alifting force thereupon in opposition to thesaid plunger depressing force, latching means for engagement with thelower end of said rack to hold said plunger in a raised position, saidlatching means being biased toward latching position but being adaptedto ride freely over the teeth of the rack, and means on said arm forwithdrawing said latching means when said arm is lowered to apredetermined extent.

WALTER W. URMETZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 832,758 Taylor Oct. 9, 19061,059,667 Gathmann Apr. 22, 1913 1,420,555 Klasing June 20, 19221,474,785 Kruger Nov. 20, 1923 1,526,125 Fellows Feb. 10, 1925 1,957,462Kress May 8, 1934 2,317,565 Urmetz Apr. 27, 1943 FOREIGN PATENTS NumberCountry Date 441,284 Germany Feb. 28, 1927

